Rotary blade for meat grinder

ABSTRACT

A meat grinder in which a worm conveyor on a horizontal shaft feeds the meat to be ground toward a rotary blade or chopper provided with radially extending blade arms. The blade arms move in a rotary path and cooperate with the surface of the perforated plate for cutting or chopping action. Each blade arm has a wedgeshaped blade block which diverges outwardly. Each blade block, as a leading edge, has a straight cutting edge for riding on the surface of the plate. This cutting edge is disposed forwardly of the radial axis of the blade arm and converges outwardly toward this radial axis. The wedge-shaped blade blocks assure even wearing of the blade blocks against the plate.

United States Patent [72] Inventor Eugene A. Anderson Lewis Place, Box 895, Douglasville, Ga. 30134 [2!] Appl. No. 764,407 [22] Filed Oct. 1 968 [45] Patented Feb. 15, 1971 [$4] ROTARY BLADE FOR MEAT GRINDER 11 Claims, 5 Drawing Figs, 521 vs. cl 146/189 [51] B02c 18/18 [50] FieldofSeai-ch l46/l89.l,

189, 186 r [56] References Cited UNITED STATES PATENTS 1,669,988 146/189 5/1928 Johnson 2,9I4,103 11/1959 Ferris Primary Examiner-Willie G. Abercrombie Attorney-Newton, Hopkins & Ormsby ABSTRACT: A meat grinder in which a worm conveyor on a horizontal shaft feeds the meat to be ground toward a rotary blade or chopper provided with radially extending blade arms. The blade arms move in a rotary path and cooperate with the surface of the perforated plate for cutting or chopping action. Each blade arm has a wedge-shaped blade block which diverges outwardly. Each blade block, as a leading edge, has a straight cutting edge for riding on the surface of the plate. This cutting edge is disposed forwardly of the radial axis of the blade arm and converges outwardly toward this radial axis. The wedge-shaped blade blocks assure even wearing of the blade blocks against the plate.

PATENTED FEBIBIQYI 3,563,291

INVENTOR.

BY g/ywlan (My,

If firmly m This invention relates toa meat grinder and is more particularly concerned with a rotary blade for Meat Grinder which operates in conjunction with the perforated plate of a meat grinder to comminute or grind meat and the like, fed against the plate.

In the past, meat grinders of the general'type, having a horizontal shaft which rotates, simultaneously, a worm conveyor and a chopper which rides against a perforated plate, have been widely used and are the usual type of meat grinder found in retail meat markets. The chopper or rotary blade of such meat grinders, when it becomes dull, tends to smear the meat along the surface of the plate, creating a cellophanelike sheet along this surface which prevents subsequent efficient cutting of the meat. Also, the tendons of the meat are wrapped around the shaft, tending to block the free flow of the meat and perhaps tending to lift the radially disposed blades away from the plate, thereby reducing the efficiency of the chopper.

Furthermore, the prior art chopper blades wear unevenly, due to the fact that the peripheral portion of the blade is moving over a far longer path, each revolution, than the hub or inner portion thereof. Thus, the cutting efficiency of the peripheral portions of the blades are reduced.

To overcome this drop in efficiency, the plate of the prior art grinder is tightened against the chopper, thereby urging the chopper blades more'firmly against this plate. Upon such tightening, since the wear on each increment of the blade is proportional to its distance from the axis and because the radially extending blades of the chopper yield more readily toward the periphery of the chopper, 'the inner or hub portions of these blades are urged more firmly against the plate. This results in more friction toward the central portion and the generation of heat in that region which possibly will burn out the plate in that region. The accompanying heating of the meat, due to such friction, may also ruin the bloom" of the meat, thereby reducing the fresh appearance of the meat and its shelflife.

Another problem with respect to the prior art chopper is that the tips or peripheral portions of the chopper, which travel at relatively high peripheral speed, sometimes break, due to sudden shock as when the blade comes in contact with bone.

Still another problem with the prior art chopper is that the meat, being ground, has a tendency to be forced to the center where it is carried around by the blade and is never ground.

BRIEF DESCRIPTION OF THE INVENTION Briefly described, the present invention, which overcomes or minimizes the difficulties described above, includes a chopper or rotary blade having a hub with circumferentially spaced radial extending blade arms, the chopper operating in conjunction with the perforated plate of a conventional meat grinder. Each blade arm carries a forwardly extending wedgeshaped blade block. The blade block has a straight cutting leading edge which is circumferentially forward of the radial axis of the blade and converges outwardly toward this radial axis so as to direct the meat outwardly as the chopper is rotated. The surface blade of the block, circumferentially rearwardly of the cutting edge, is provided with a flat narrow or hairline beveled blade surface having a trailing blade surface edge which forms a common edge with the major face surface of the blade block. The trailing edge of the blade block diverges outwardly from the cutting edge, intersecting the radial axis of the blade arm. By such an arrangement, progressively more metal is provided on the blade block, the amount of metal being proportional to itsdistance from the axis of rotation of the blade or chopper.

Accordingly, it is an object of the present invention to pro vide a rotary blade for a meat grinder, the blade being inexpensive to manufacture, durable in structure and efficient in operation.

Another object of the present invention is to provide a rotary blade for a meat grinder, the blade having an improved or increased useful blade life.

Another object of the present invention is to provide, in a meat grinder, a rotary blade in which the cutting edges wear more evenly Another object of the present invention is to provide, in a meat grinder, a rotary blade which will distribute the meat evenly along its cutting edge for chopping action and will not direct the meat toward the center or axis of rotation of the blade.

Another object of the invention is to provide a rotary blade for meat grinder, the blade being more resistant to breakage.

Another object of the invention isto provide a rotary blade for a meat grinder, the blade being so constructed as to facilitate the passage of meat through the grinder with less heating of the meat, less pressure on the meat and reduced wear on the blade.

Another object of the present invention is to provide a blade for the above-described purposes which is less likely to break adjacent its blade arm tips.

Another object of the present invention is to provide a blade for the above-described purposes which will not cause burning or cracking of the center portion of the perforated plate with which it operates.

Another object of the present invention is to provide a blade for the purposes above described. which will cut the meat adjacent the center of the plate more easily.

Another object of the present'irivention is toprovide a blade for grinding meat, the blade rendering the ground meat with a longer shelf life and better in appearance.

Other objects, features and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings wherein like characters of reference designate corresponding parts throughout the several views, and wherein:

BRIEF DESCRIPTION OF THE DRAWING FIGURES FIG. 1 is an exploded perspective view of a conventional meat grinder provided with a chopper or rotary blade constructed in accordance with the present invention;

FIG. 2 is a cross-sectional view taken substantially along line 2-2 in FIG. 1; t

FIG. 3 is an enlarged'rear elevational view of the rotary blade of the present invention;

FIG. 4 is fragmentary front elevational view of one blade arm of the rotary blade of the present invention; and

FIG. 5 is a cross-sectional view taken substantially along line 5-5 in FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION Referring now in detail to the embodiment chosen for the purpose of illustrating the present invention and particularly to FIG. 1 of the drawing, the horizontal meat grinder depicted therein includes a motor 10 mounted on a base 11, the motor 10 carrying a sidewise projecting hollow tubular grinder housing 12. A tubular feed chute 13, having its hollow interior communicating with the interior of the housing 12, provides a means by which meat, vegetable or other fibrous material to be comminuted is fed to the grinder.

Within the grinder housing 12 is the usual worm conveyor 14 which is rotated about its axis by motor 10. The worm gear 14 feeds the meat received through chute l3 forwardly in housing 12. The outer, i.e., forward end of worm conveyor I4 is provided with an axially disposed forwardly extending shaft squared at numeral 15 for removably receiving the rotary blade or chopper, denoted generally by numeral 20.

The front of blade 20 is urged against the usual disc-shaped, perforated plate 16 which is received at the end of housing 12. Inwardly protruding fingers 17 on the inner periphery of housing 12, received in the peripheral notches 18 on plate I6, prevent rotation of the plate while a collar 19, threadedly received on the external threads 21 of housing 12, retains plate 16 in place.

As best seen in FIG. 2, the plate 16 includes a flat polished inner surface 22, a flat outer surface 23 parallel to inner surface 22 and a plurality of circular perforations 24.

With the exception of the rotary blade or chopper 20, the structure thus far described is conventional.

The rotary" blade or chopper includes a hub 25 from which radiate four equally circumferentially spaced blade arms 26. The hub 25 has a square central opening 27 of appropriate dimensions to be received on the squared portion of shaft 15 and be rotated thereby about its major axis A or rota tion of axis A in a clockwise direction, as viewed in H6. 3.

Each of the blade arms 26 is identical and carries identical wedge-shaped blade blocks 28. In more detail, each blade arm 26 extends radially outwardly from a corner of the square hub 25 and is integrally joined by its proximal end to hub 25.

The rear side of each arm 26 is convex, arcing transversely. The leading edge 29 and trailing edge 30 of each arm 26 are disposed on opposite sides of the radial axis A and taper or converge outwardly toward the distal end 31 of arm 26.

in the region of hub 25, each leading edge 29 merges with the trailing edge of the next adjacent blade arm 26, defining a concaved abutment edge 32.

The forward surface 33 of each arm 26 is flat, being disposed in a common radial plane with the other forward surfaces 33.

The wedge-shaped blade block 28 for each arm 26 is mounted, as by brazing, to the forward surface 33 and has a leading edge 34 in a common plane with the leading edge 29 of blade arm 26. Also, the outer end 35 of blade block 28 is in a common rearwardly inclined plane with the distal end 31 of blade arm 26, the end 35 being substantially as wide as the end 31.

The trailing edge 36 of the blade blocks 28 diverges outwardly, or stated another way, converges inwardly toward the leading edge 34 and intersects axis A at its proximal end; the blade block 28 terminates outwardly of square hub 25 in a short transverse inner end 37, connecting the ends of edges 34 and 36.

The inner surface of the blade block 28 has a pair of abutting flat surfaces which are joined along a common edge 38, the common edge 38 lying parallel to and spaced slightly from the leading or cutting edge 34 so as to define therebetween a hairline beveled edge or surface 40. Surface 40 is inclined slightly at about 4 from the radial plane. In addition, cutting edge 34 has a bevel angle between the forward surface of blade block 28 and the beveled surface 40, of preferably approximately 77 and between 60 and 90.

Rearwardly of the common edge 38, the major or face surface 41 of the blade block 28 is inclined at a greater angle then the angle of hairline surface 40, this relief angle a between the radial plane and the surface 41 being approximately 8 and between approximately 6 and approximately 30.

In a standard size grinder, the thickness of blade block 28 is approximately three-sixteenths inch. Also, the block 28 tapers from approximately seven-sixteenths inch in width, adjacent end 35, to approximately one-sixteenth, adjacent end 37.

The blade 20, when operating, is urged flat against the inner surface 2 ofplate l6 and is rotated about its axis A, when conveyor 14 is rotated, thereby slicing the meat as the meat is urged by conveyor 14 through the holes 24.

The progressively larger area toward the periphery of the blade blocks 28 provides correspondingly more area to be ground away, and progressively less area inwardly thereof. Since the periphery of blade 20 travels a greater distance each revolution, the blade block 28 tends to wear evenly, throughout its length. Also, due to the relatively large cross section of block 28, in the peripheral region, the tip is less likely to break. Heat which is generated at a greater rate in the peripheral region is, likewise, conducted away faster, due to thF inr-rnocnri width nf hlnrir IR The even wear of the blade blocks 28 prevent producing high cutting areas adjacent the hub 25 and assure a close fit between the surface 22 and each edge 34 throughout the length of the blade block 28. Also, the elimination of the high center areas on blocks 28 prevents a tendency of these high center areas to burn out the center of plate 16.

The angling or tapering of cutting edge 34 toward the tip end 35 (with respect to axis A directs the meat outwardly where it can be cut more efficiently and reduces the likelihood that the meat will be clogged adjacent HUB 25. The relief angle a and the angling trailing edge 36 also aid in directing the meat from the hub region outwardly.

The improved efficiency of my rotary blade 20, for the reasons discussed above, reduces the power required, reduces the friction and heat and thereby enables a uniformly high quality ground product to be produced which has an extended shelf life. Also, the useful life of plate 16 and blade 20 is extended while the shutdown time for the grinder is decreased.

Iclaim:

1. A rotary blade for grinder of the type which has a hub provided with an axis of rotation and radially extending blade arms radiating from the hub, the blade being adapted to be rotated about its axis adjacent one face of a perforated plate for chopping material urged against the plate and into the apertures therein, the combination with said radially extending blade arms of a plurality of progressively wider blade blocks carried respectively by said blade arms for riding against said face of said plate for providing a blade edge which chops the material, each of said blade blocks having an inner surface inclined from the radial plane of said axis of rotation and a front surface, said inner surfaceand said front face forming said blade edge at the forward portion of each block.

2. The rotary blade for grinder as set forth in claim I wherein said blade blocks each have a trailing edge tapering inwardly with respect to said blade edge.

3. The rotary blade for grinder as set forth in claim 1 wherein each of said blade blocks is wedge-shaped and tapers inwardly.

4. The rotary blade for grinder as set forth in claim 1 wherein each of said blade blocks is provided with a face surface having a relief angle with respect to the radial plane of said axis of rotation of between approximately 30 and approximately 5. The rotary blade for grinder as set forth in claim 1 wherein the inner end of each of said blade blocks is spaced outwardly of said axis of rotation and each of said blade blocks is wedge-shaped having the wider portion thereof adjacent the distal end of its associated blade arm.

6. The rotary blade for grinder as set forth in claim 1 wherein said cutting edge is forward of the radial axis of its associated blade arm in the direction of rotation of the blade and converges outwardly toward said radial axis.

7. The rotary blade for grinder as set forth in claim 1 wherein said inner surface includes a beveled surface adjacent said front face and a major surface intersecting said beveled surface, said major surface being at a greater angle from the radial plane than said beveled surface.

8. The rotary blade for grinder as set forth in claim 7 wherein said front surface is inclined rearwardly and wherein said beveled surface is disposed at an acute angle to the radial plane of said rotary blade.

9. The rotary blade for grinder as set forth in claim 7 wherein the angle subtended between said front surface and beveled surface is betweenapproximately 60 and approximately 90.

10. The rotary blade for grinder as set forth in claim 9 wherein said blade block is provided with a face surface intersecting said beveled surface, said face surface being rearwardly of said beveled surface and disposed at a greater angle to said radial plane than said beveled surface.

11. The rotary blade for grinder as set forth in claim 10 wherein said acute angle. between the radial plane and said face surface is between approximately 6 and approximately 30 

1. A rotary blade for grinder of the type which has a hub provided with an axis of rotation and radially extending blade arms radiating from the hub, the blade being adapted to be rotated about its axis adjacent one face of a perforated plate for chopping material urged against the plate and into the apertures therein, the combination with said radially extending blade arms of a plurality of progressively wider blade blocks carried respectively by said blade arms for riding against said face of said plate for providing a blade edge which chops the material, each of said blade blocks having an inner surface inclined from the radial plane of said axis of rotation and a front surface, said inner surface and said front face forming said blade edge at the forward portion of each block.
 2. The rotary blade for grinder as set forth in claim 1 wherein said blade blocks each have a trailing edge tapering inwardly with respect to said blade edge.
 3. The rotary blade for grinder as set forth in claim 1 wherein each of said blade blocks is wedge-shaped and tapers inwardly.
 4. The rotary blade for grinder as set forth in claim 1 wherein each of said blade blocks is provided with a face surface having a relief angle with respect to the radial plane of said axis of rotation of between approximately 30* and approximately 90*.
 5. The rotary blade for grinder as set forth in claim 1 wherein the inner end of each of said blade blocks is spaced outwardly of said axis of rotation and each of said blade blocks is wedge-shaped having the wider portion thereof adjacent the distal end of its associated blade arm.
 6. The rotary blade for grinder as set forth in claim 1 wherein said cutting edge is forward of the radial axis of its associated blade arm in the direction of rotation of The blade and converges outwardly toward said radial axis.
 7. The rotary blade for grinder as set forth in claim 1 wherein said inner surface includes a beveled surface adjacent said front face and a major surface intersecting said beveled surface, said major surface being at a greater angle from the radial plane than said beveled surface.
 8. The rotary blade for grinder as set forth in claim 7 wherein said front surface is inclined rearwardly and wherein said beveled surface is disposed at an acute angle to the radial plane of said rotary blade.
 9. The rotary blade for grinder as set forth in claim 7 wherein the angle subtended between said front surface and beveled surface is between approximately 60* and approximately 90*.
 10. The rotary blade for grinder as set forth in claim 9 wherein said blade block is provided with a face surface intersecting said beveled surface, said face surface being rearwardly of said beveled surface and disposed at a greater angle to said radial plane than said beveled surface.
 11. The rotary blade for grinder as set forth in claim 10 wherein said acute angle between the radial plane and said face surface is between approximately 6* and approximately 30*. 